/*
Copyright (c) 2009, Heinrich C. Spreiter
All rights reserved.

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

  - Redistributions of source code must retain the above copyright notice,
  this list of conditions and the following disclaimer.
  
  - Redistributions in binary form must reproduce the above copyright notice,
  this list of conditions and the following disclaimer in the documentation
  and/or other materials provided with the distribution.
  
  - Neither the name of the author nor the names of its contributors may be used
  to endorse or promote products derived from this software without specific
  prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package ch.kynlang.compiler.scope;

import java.util.Iterator;
import java.util.LinkedHashMap;
import ch.kynlang.compiler.symbol.Symbol;

/*
 * RootScope.java
 *
 * @version 0.1 27.12.2009
 * @author HSP spreiter301@gmail.com
 * 
 * Holds all symbols
 */
public class RootScope implements IScope, Iterable<Symbol> {
	private LinkedHashMap<String, Symbol> symbols = null;
	
	public RootScope() {
		symbols = new LinkedHashMap<String, Symbol>();
	}
	
	@Override
	public boolean define(Symbol symbol) {
		if(!symbols.containsKey(symbol.name)) {
			symbols.put(symbol.name, symbol);
			return true;
		}
		return false;
	}

	@Override
	public IScope getParentScope() {
		return null;
	}

	@Override
	public Symbol resolve(String symbolName) {
		return symbols.get(symbolName);
	}

	@Override
	public Iterator<Symbol> iterator() {
		final Iterator<String> keys = symbols.keySet().iterator();
		
		Iterator<Symbol> iterator = new Iterator<Symbol>() {
			
			@Override
			public void remove() {
				throw new UnsupportedOperationException("remove is not supported");
			}
			
			@Override
			public Symbol next() {
				return symbols.get(keys.next());
			}
			
			@Override
			public boolean hasNext() {
				return keys.hasNext();
			}
		};
		return iterator;
	}

}
